Knock-on sweep structure and tools therefor

ABSTRACT

Sweep retaining structure includes a spring wire retainer with a base supported in a groove on the underside of the wedge support which mates with a stem portion of the sweep. The wedge support is apertured, and a central curved portion of the retainer passes through the aperture and supports a sweep-contacting end above the surface of the wedge support. The end is biased toward a contact area on the sweep to engage the area and eliminate sweep loss problems by preventing the sweep from slipping downwardly from the mounted position. To remove the sweep, a tool is inserted through the slot to depress the retainer end, and the sweep is forced off the wedge support. A raised area on the sweep directs soil away from the retainer and contact area to reduce wear and eliminate depression of the end during operation. The underside of the raised area positions the wire end and provides bend-resisting support for the wire.

FIELD OF THE INVENTION

The present invention relates generally to tillage tools and, morespecifically, to a knock-on sweep and structure for preventing the sweepfrom falling off the end of a shank.

BACKGROUND OF THE INVENTION

Standard assemblies for implements such as chisel plows and fieldcultivators typically include a spring trip shank assembly extendingdownwardly to a tool-receiving end which mounts a shovel, point orsweep. Previously available mounting structure included bolts extendingthrough holes in the tool and the shank to secure the tool. When thetool in such an assembly has to be replaced because of wear or damage,the bolts must be removed. Wear and corrosion of the bolts substantiallyhinders removal and often makes the replacement a difficult andtime-consuming task.

Several solutions to the problem of easily and quickly replacing wornelements such as sweeps on shanks have been developed over the years,including adapter brackets providing a self-locking fit with a matchingtaper on knock-on sweeps. Frangible pins and bolts have also beensuggested. However, most retaining devices have suffered from one ormore problems, including need for additional parts and the loss ofsweeps when encountering high removal forces during transport and duringrebounding of the shank from a tripped position. To reduce incidences ofsweeps falling off the shanks in quick mount arrangements, somemanufacturers have offered detent mechanisms such as a retaining clip inthe form of a sheet metal stamping with a spherical protrusion that fitsinto a hole in the sweep. To release the sweep, a screwdriver or othertool is used to depress the clip and move the protrusion away from thehole. Other detent arrangements are shown, for example, in U.S. Pat.Nos. 3,061,021 and 6,289,996. Such detents generally help retain thesweeps on the shanks, but the forces exerted on a sweep, particularlyforces exerted on deep tillage tools, can be so great that the sweepfails to stay on the shank. The geometry of most previously availablesweep detent arrangements, including non-symmetrical mating surfaces onsome, usually limits penetration of the retaining surface into the holeso that retaining forces are limited. Some care must be taken to alignthe protrusion with the hole, and part tolerances, variations in forceused to mount the sweep, or lack of indexing of the clip relative to theshank can make such alignment troublesome. A relatively small, rampedcontact area between the clip and the hole also increases the potentialfor losing a sweep. Soil moving up and around the stem portion of thesweep can move the clip from the detent position or wear away the clipuntil it is ineffective for holding the sweep on the shank. Extremeforces on the detent, such as those which occur during rebound, can alsocause deformation of the detent. If the detent deforms, loosened sweepscan unacceptably dangle from the shank or be lost. A hefty detentconstruction or frequent detent replacements are therefore usuallyrequired.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide animproved sweep retaining structure for a knock-on sweep that overcomesmost or all of the above-mentioned problems. It is another object toprovide such an improved sweep retaining structure which is simple andinexpensive to manufacture and assemble and yet reliably holds the sweepon the shank and facilitates quick and easy removal of the sweep.Further objects include providing an improved sweep and providing animproved retainer for use with such structure.

It is yet another object to provide an improved sweep retainingstructure which provides reliable retention independently ofmanufacturing tolerances, forces applied during sweep mounting andprecise alignment of mating portions of the sweep assembly. It isanother object to provide such a structure having an improved andsimplified retainer mounting arrangement. It is a further object toprovide such a structure wherein the retainer is positioned for properengagement with a contact area on the sweep without direct contact witha bolt or similar fastener. It is still another object to provide such astructure having support and guidance structure for the detent tofacilitate alignment and prevent bending of the detent.

It is yet another object to provide an improved sweep retainingstructure which eliminates need for flat retaining clips and whichprovides improved wear and retaining characteristics compared to atleast most previously available clip type retaining structures. It isanother object to provide such a sweep retaining structure with integralretainer guide and wear reducing structure for improving retention andpreventing retainer deformation.

Sweep retaining structure constructed in accordance with the teachingsof the present invention includes a retainer fabricated from wire springmaterial and including a bent wire base supported in a groove on theunderside of the wedge support which mates with stem portion of thesweep. The wedge support is apertured, and a central curved portion ofthe retainer passes through the aperture and supports a sweep-contactingend above the surface of the wedge support. The end is biased toward acontact area on the sweep, preferably the top edge of a slot in thestem, to engage the area and eliminate sweep loss problems by preventingthe sweep from slipping down away from the wedged mounted position. Toremove the sweep, a tool is inserted through the slot to depress theretainer end, and the sweep is forced downwardly off the wedge support.

The retainer is simple, inexpensive and reliable. The groove supporteliminates a separate retainer fastening bolt or contact with afastening bolt and improves ease of assembly, proper positioning andwearability of the retainer. The retainer can be easily slipped intoposition on the wedge support.

The slot in the stem is preferably located near the top of theconnecting portion and defines an end contact edge. To protect the edgeand the end of the retainer from wear as well as prevent soil and debrisfrom depressing the end, a portion of the stem directly ahead of theslot is raised relative to the remainder of the surface of the stem andrelative to the contact edge. The raised portion directs the soil anddebris away from the slot. The underside of the raised portion defines aretainer guiding and support channel which holds the wire end in theoptimum sweep locking position and provides support for the wire toeliminate retainer deformation when high sweep removal forces areencountered during operation. The operator can clearly see if the sweepis properly wedged onto the sweep support by simply viewing the positionof the wire end relative to the contact edge and the guiding and supportchannel.

In one embodiment of the sweep, a central portion just below the stemalso includes a raised area to help direct material away from the stemto improve stem life and assist in reducing wear in the slot area and inthe end of the retainer.

These and other objects, features and advantages of the presentinvention will become apparent to one skilled in the art upon readingthe following detailed description in view of the drawings.

BRIEF DESCRIPTION OF THE INVENTION

FIG. 1 is a side perspective view of a lower portion of a shank assemblyincluding a sweep and sweep retaining structure constructed inaccordance with the teachings of the present invention.

FIG. 2 is an enlarged bottom perspective view of a portion of theassembly of FIG. 1, partially cut away to better show the sweepretaining structure and including a portion of a sweep removing tool.

FIG. 3 is a top view of the retainer for the structure of FIGS. 1 and 2.

FIG. 4 is a side view of the retainer of FIG. 3.

FIG. 5 is a perspective view of the retainer of FIG. 3.

FIG. 6 is an enlarged perspective view of the sweep removing tool ofFIG. 2.

FIG. 7 is a view similar to FIG. 1 and including a modified version of atool having sweep attaching, sweep removing and dirt removing structure,the tool shown in a position for mounting the sweep.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, therein is shown the lower portion of a springtrip shank assembly 10 including a shank 12 having a lower tool-mountingend 14 supporting a knock-on sweep assembly 18. The assembly 18 includesa wedge-shaped adapter bracket or sweep support 20 having an aft faceconforming to the forward face of the end 14. The support 20 is securedto the end by two plow bolts (not shown) extending through apertures 22(FIG. 2) in the sweep support 20 and corresponding apertures in the end14 of the shank 12. An earthworking tool 30, shown as a sweep in FIGS. 1and 2, includes a forwardmost tip or point 32 and opposed wing portions34 diverging outwardly in the rearward direction. An downwardly andrearwardly concave sweep mounting portion or stem 36 includes edges 38which wrap partially around the bracket 20. The portion 36 provides awedge fit between the tool 30 and the lower end 14 of the shank 12 whenthe tool 30 is knocked on the sweep support 20. The portion 36 is slidupwardly over the bracket 20 and then the tool 30 is driven upwardly andrearwardly by several sharp blows from a hammer to wedge the tool intothe mounted position on the shank 12.

The sweep mounting portion 36 and the sweep support 20 firmly supportthe tool 30 on the end 14 without need for mounting bolts directlyconnected to the sweep 30. Since sweep mounting bolts are eliminated,the sweeps can be quickly driven from the support 20 and easilyreplaced. However, rebound forces and the like can loosen the wedge fitwhile operating in the field. To prevent loss of the tool 30 if thewedge fit is loosened during operation, retaining structure indicatedgenerally at 40 is provided. The normal forces operating on a sweepworking in the ground tend to urge the sweep back into the wedge fit ormounted position if the sweep can be retained on the sweep support 20after the undesired loosening.

The sweep retaining structure 40 includes a contact area 50 centrallylocated at the upper portion of the stem or attaching portion 36. A bentwire retainer 54 made of spring steel having a generally round crosssection is carried by the sweep support 20 and includes a contact end 58which is offset forwardly and above the top or forward surface of thesweep support 20. The contact end 58 is biased into a locking position(FIGS. 1 and 2) wherein the flat end 58 abuts the mating flat contactarea 50 when the sweep 30 is in the mounted position as shown. Thesurfaces of the area 50 and the end 58 are preferably parallel to eachother when in contact. The contact prevents the sweep from moving awayfrom the mounted position until the end 58 is moved toward the sweepsupport 20 against the bias.

The sweep support 20 includes an aperture 60 (FIG. 2) located betweenthe plow bolt receiving apertures 22, and the bent wire retainer 54includes a central portion 54 c which projects through the aperture 60.The bent wire retainer 54 includes a bent wire base portion 54 b whichlies generally in a plane. The sweep support 20 has a front side 20 ffacing the sweep stem 36 and an opposite rear side 20 r, and the bentwire base portion 54 b is supported in an arc-shaped groove 66 partiallysurrounding the top plow bolt aperture 22 on the rear side 20 r. Thebase 54 b of the bent wire retainer 54 is captured between the forwardface of the shank end 14 and the groove 66 when the support 20 isattached to the shank 12. Good wire retainer support and positioning isthus provided independently of any separate fasteners or need forcontact with a plow bolt. During assembly, the end 58 of the bent wireretainer 54 is simply inserted through the aperture 60, and the baseportion 54 b is positioned in the groove 66.

The stem 36 of the sweep 30 includes a raised soil deflection area 70which also defines a retainer guiding and support area on the undersideof the raised area. The underside of the raised area 70 is concavedownwardly and rearwardly and opens in the rearward direction towardsthe contact area 50 (see FIGS. 2 and 4). The underside of the area 70receives a portion of the bent wire retainer at a location 54 g offsetfrom the end 58 and guides the end 58 towards the contact area 50 as thesweep 30 is driven towards the wedged mounted position. The wireretainer 54 is bent adjacent the location 54 g (see FIGS. 4 and 5) sothe axis 58 a of the end 58 is substantially perpendicular to the planeof the contact area 50. The contact area 50 is preferably the aft edgeof a slot 72 located rearwardly adjacent the raised area 70. The top ofthe edge lies along surface 36 t of the stem 36 and is protected by theraised area 70 which extends a substantial distance above the surface todeflect dirt and debris away from the edge and the retainer 54.

The rearward face of the end 58 is parallel to the plane of the contactarea 50 when the sweep is mounted and the end 58 of the bent wireretainer 54 is in the locking position. As the sweep is driven upwardlyand rearwardly onto the sweep support 20, the end 58 is urged downwardlyuntil the contact area 50 passes the end 58 of the retainer. Thelocation 54 g then springs into the channel-shaped underside of the area70 so the end 58 is held in the proper position relative to the contactarea (FIG. 4). If the sweep 30 begins to move downwardly away from thewedged position, the contact between the end 58 and the contact area 50holds the sweep closely adjacent the fully wedged position until thesoil forces acting on the sweep during operation again wedge the sweepinto the locked position. The channel-shaped underside at 70 alsosupports the end 58 of the wire retainer 54 at points generally on-axisto help the retainer resist bending moments that would otherwise occurwhen strong sweep-removing forces such as rebound forces are acting todislodge the sweep. Without the support of the channel-shaped underside,the retainer could easily be deformed by the forces.

Referring to FIGS. 2 and 6, a removal tool 80 is shown which includes ahandle 82 supporting a removal end 84 with a support 86 adapted forpositioning against the assembly 10 and a retainer depressing extension88 positioned above the slot 72 and the end 58. The handle 82 is movedtowards the sweep 30 to depress the end of the wire retainer 54 belowthe contact area 50. A hammer is then used to impact a flat surface 90above the removal end 84 to drive the sweep from the assembly.Transversely spaced ears 92 engage the top edge of the stem 36 forpositive tool positioning and sweep engagement and good distribution ofimpact forces.

In an alternate embodiment 80′ shown in FIG. 7, an attaching tool 100 issupported from the handle 82′ and includes a V-shaped member 102generally conforming to the forward soil engaging portion of the sweep30 and adapted for being slidably received over the sweep as shown. Aflattened impact area 110 is offset from the sweep point on the side ofthe handle opposite the member 102. After slipping the sweep 30 onto thesweep support 20, the operator can wedge the sweep in the securedposition by hitting the area 110 with several sharp blows of a hammer.The member 102 covers the leading point and edge area, distributes thedriving force and protects the sweep from damage. A screwdriverattachment or soil engaging end 112 is attached to the end of the handle82′ opposite the removal end 84.

An additional raised area 120 is formed in the surface of the sweep 30rearwardly of the point 32 just below the area where the stem 36connects to the remainder of the sweep. The raised area directs soil anddebris outwardly from the stem 36 to increase stem wear life. Inaddition, the area 120 aids the raised area 70 in directing soil awayfrom the retainer 54 and the contact area 50 for more reliable sweepretention and increased sweep retainer structure life.

Having described the preferred embodiment, it will become apparent thatvarious modifications can be made without departing from the scope ofthe invention as defined in the accompanying claims.

We claim:
 1. A knock-on sweep assembly for a tillage implement sweephaving a forward cutting edge, the assembly including a sweep support, asweep mounting portion located rearwardly of the cutting edge and matingwith the sweep support, the sweep mounting portion providing afastenerless tight but releasable fit when the sweep is in a mountedposition on the sweep support, and retaining structure for preventingthe sweep from dislodging from the sweep support, the retainingstructure including a contact area on the mounting portion, and a bentwire retainer supported by the sweep support and having an end, the endoffset from the sweep support and biased into a locking position whereinthe end abuts the contact area when the sweep is in the mounted positionand prevents the sweep from moving away from the mounted position untilthe end is moved toward the sweep support against the bias.
 2. The sweepassembly as set forth in claim 1 wherein the sweep support is apertured,and the bent wire retainer projects through the aperture.
 3. The sweepassembly as set forth in claim 2 wherein the bent wire retainer includesa bent wire base portion, the sweep support has a front side facing thesweep and an opposite rear side, and the bent wire base portion issupported on the rear side.
 4. The sweep assembly as set forth in claim1 wherein the sweep includes a retainer guiding and support areareceiving a portion of the bent wire retainer at a location offset fromthe end and guiding the end towards the contact area during mounting ofthe sweep and supporting the end in alignment with the contact area. 5.The sweep assembly as set forth in claim 4 wherein the sweep mountingportion includes a surface and the contact area extends downwardly fromthe surface, and wherein the retainer guiding and support area comprisesa raised portion projecting above the surface to prevent soil fromwearing the contact area and preventing the end from being moved againstthe bias toward the sweep support by the soil.
 6. The sweep assembly asset forth in claim 1 wherein the contact area comprises a slot in thesweep mounting portion having a rearward edge contacting the end whenthe sweep is in the mounted position and the end is in the lockingposition.
 7. A knock-on sweep assembly for mounting a tillage implementsweep with a forward soil entry portion including a cutting edge onshank structure, the assembly including a sweep support connected to theshank structure, a sweep mounting portion located rearwardly of thecutting edge and mating with the sweep support, the sweep mountingportion providing a fastenerless tight but releasable fit when the sweepis in a mounted position on the sweep support, and retaining structurefor preventing the sweep from dislodging from the sweep support, theretaining structure including a contact area on the mounting portion,and a retainer supported by the sweep support and having an end, the endoffset from the sweep support and biased into a locking position whereinthe end abuts the contact area when the sweep is in the mounted positionand prevents the sweep from moving away from the mounted position untilthe end is moved toward the sweep support against the bias, and whereinthe sweep mounting portion includes a raised soil-deflecting portionlocated forwardly of the contact area on the mounting portion fordirecting soil and debris away from the contact area, the raisedsoil-deflecting portion defining a retainer receiving cavity providingsupport for the retainer when the end is in the locking position tothereby help the retainer resist bending forces.
 8. The sweep assemblyas set forth in claim 7 wherein the retainer comprises a bent wire. 9.The sweep assembly as set forth in claim 8 including an aperture havingan edge defining the contact area on the mounting portion and whereinthe bent wire includes an end portion having an axis extendingperpendicularly to the contact area and an end face parallel to thecontact area, and wherein a section of the wire adjacent the end portionis received within the cavity.
 10. The sweep assembly as set forth inclaim 7 including a soil deflecting surface located between the cuttingedge and the raised soil-deflecting portion for directing soil anddebris away from the mounting portion and the contact area.